1. Field of the Invention
The present invention relates to an image forming apparatus for forming a monochromatic image or a full color image by employing, for example, an ink jet recording process, a thermal transferring process or an electronic photographing process. Further, the present invention relates to an image forming method to be practiced by the image forming apparatus.
2. Description of the Related Art
In recent years, many kinds of image forming apparatuses which form an image on a recording medium by employing an ink jet recording process, a thermal transferring process or an electronic photographing process have been developed.
Among the above-mentioned recording processes, the ink jet recording process is a so-called non-impact type recording process which makes it possible to form an image on various kinds of recording medium such as plain paper or the like by ejecting ink onto the recording medium so as to allow the ejected ink to adhere to the recording medium. However, in the case that a full color image is formed on the recording medium using plural inks of different colors, a large quantity of inks are unavoidably shot onto the recording medium. For this reason, there arise malfunctions that extra ink flows between adjacent dots on the surface of the recording medium depending on properties of the recording medium. Moreover, ink oozing appears on the recording medium resulting in degraded image.
Also in the case that a monochromatic image is formed on a recording medium, if a large area of the recording medium is fully coated with ink or if a photographic image is formed on the recording medium, a large quantity of ink is shot onto the recording medium compared with the case that characters or line-shaped figures are formed on the recording medium. This results in the same or similar malfunctions.
To form excellent images on a recording medium by an ink jet recording apparatus, it is desirable to employ exclusively usable papers (hereinafter referred to as EU papers) which are coated with an ink absorbing layer and a color appearance layer. Incidentally, EU paper is usually prepared in the form of a coated paper. Also in the case that a halftone image such as a photograph assuring a high quality of image is to be formed on a recording medium by the thermal transferring process, it is desirable to employ an EU paper having excellent surface flatness to improve a property of color appearance.
To form a halftone image having a high quality on a recording medium by the electronic photographing process, it is also desirable to employ an EU paper having an excellent surface flatness.
In practice, however, a user selects the recording medium to be used at his discretion. After the selection, image is formed on the recording mediums selected by the user.